Thrust vectoring apparatus, thrust vectoring method, and flying body

ABSTRACT

A first jet tab and a second jet tab are symmetrically arranged with respect to a first symmetry plane and have a symmetrical shape with respect to the first symmetry plane, and are symmetrically driven with respect to the first symmetry plane by a driving section. A distance between a tip sensation of the first jet tab and a first rotation axis is larger than a distance between the first rotation axis and the first symmetry plane. A distance between a tip section of the second jet tab and a second rotation axis is larger than a distance between the second rotation axis and the first symmetry plane.

CROSS-REFERENCE

This application is based on Japanese Patent application JP 2014-213077and claims a priority of it. The disclosure thereof is incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to a thrust vectoring apparatus, a thrustvectoring method, and a flying object.

BACKGROUND ART

As a technique for vectoring the thrust of a flying object, the thrustvectoring apparatus of a jet tab type is known. The thrust vectoringapparatus of this type is loaded on the flying object (e.g. a missile).Hereinafter, the thrust vectoring apparatus of this type is merelycalled the “thrust vectoring apparatus”.

The thrust vectoring apparatus operates roughly as follows. All of theplurality of tabs are in a position at which the tabs do not overlapwith a nozzle exit. When the thrust direction of the flying object isvectored to a predetermined direction (e.g. a direction of increasing apitch angle), one tab as an object of the plurality of tabs is driven toa position so as to overlap with the nozzle exit. Thus, the combustiongas which is exhausted from the nozzle hits the tab as the object sothat the direction of the combustion gas flow changes. According to thechange, the flying object orbit changes. Patent Literature 1 whichrelates to the thrust vectoring apparatus proposes a solution of theproblem that a necessary rolling moment is not obtained. PatentLiterature 2 proposes an improvement of the jet tab itself that shouldimprove the flight control of the flying object.

CITATION LIST

[Patent Literature 1] JP H04-297800A

[Patent Literature 2] JP 2012-202222A

SUMMARY OF THE INVENTION

When a thrust vectoring apparatus is loaded in a flying object, it isdesirable that the thrust vectoring apparatus is smaller. Therefore, theinventors of the present invention aimed at the downsizing andlightening of the thrust vectoring apparatus.

The thrust vectoring apparatus in the first viewpoint of the presentinvention a nozzle which has a nozzle exit which exhausts a combustiongas, a first jet tab which rotates around a first rotation axis, asecond jet tab which rotates around a second rotation axis, and at leastone driving section to rotate the first jet tab around the firstrotation axis and to rotate the second jet tab around the secondrotation axis. When a first direction is defined as a directionorthogonal to a plane of the nozzle exit and directing from an inside ofthe nozzle to an outside of the nozzle, the first jet tab and the secondjet tab are arranged in the first direction from the nozzle. The firstjet tab includes: a first proximal section arranged so as not tooverlaps with the nozzle exit in the first direction and connected withthe first rotation axis; and a first tip section configured to bemoveable from a first standby position where the first jet tab does notoverlaps with the nozzle exit, to a first work position where the firsttip section overlaps with the nozzle exit. The second jet tab includes:a second proximal section arranged so as not to overlaps with the nozzleexit in the first direction and connected with the second rotation axis;and a second tip section configured to be moveable from a first standbyposition where the first jet tab does not overlaps with the nozzle exit,to a first work position where the first tip section overlaps with thenozzle exit. The first jet tab and the second jet tab are symmetricallyarranged with respect to a predetermined first symmetry plane, have asymmetrical shape with respect to the first symmetry plane, and aredriven symmetrically with respect to the first symmetry plane by thedriving section. A distance between a tip section of the first jet taband the first rotation axis is larger than a distance between the firstrotation axis and the first symmetry plane. A distance between a tipsection of the second jet tab and the second rotation axis is largerthan a distance between the second rotation axis and the first symmetryplane.

The thrust vectoring apparatus further includes: a drive control sectionconfigured to the driving section. The driving section includes: a firstdriving section configured to rotate the first jet tab around the firstrotation axis; and a second driving section configured to rotate thesecond jet tab around the second rotation axis. The drive controlsection synchronously controls the first driving section and the seconddriving section to drive the first jet tab and the second jet tabsymmetrically with respect to the first symmetry plane.

The thrust vectoring apparatus further includes: a power dividingmechanism configured to transfer a power of the driving section to thefirst jet tab and the second jet tab at a same time.

Desirably, the power dividing mechanism includes: a first shaftconnected to the first jet tab at its one end section; a first geardisposed in the first shaft; a second shaft connected to the second jettab at its one end section and to the driving section at its proximalsection; and a second gear disposed in the second shaft. The first gearis arranged to engage with the second gear.

The first jet tab includes a first inner surface. The second jet tabincludes a second inner surface. The first inner surface and the secondinner surface are parallel to each other to face to each other when thefirst jet tab is in a first work position and the second jet tab is inthe second work position.

The first jet tab has a shape in which the first tip section becomesthinner toward a tip, and the second jet tab has a shape in which thesecond tip section becomes thinner toward a tip.

Desirably, a thickness of the first tip section becomes thinner thanthat of the first proximal section, and a thickness of the second tipsection becomes thinner than that of the second proximal section.

The thrust vectoring apparatus further includes a plurality of jet tabsets, each of which comprises the first jet tab and the second jet tab.

Desirably, the plurality of jet tab sets are arranged so that theplurality of jet tab sets do not interfere with each other even if theplurality of je tab sets are driven at a same time.

Desirably, a flying object has the thrust vectoring apparatus.

A thrust vectoring method uses a thrust vectoring apparatus. The thrustvectoring apparatus includes: a nozzle having a nozzle exit to emit acombustion gas; a first jet tab configured to rotate around a firstrotation axis; a second jet tab configured to rotate around a secondrotation axis; and at least one driving section configured to drive thefirst jet tab and the second jet tab to rotate around the first rotationaxis and the second rotation axis, respectively. When a first directionis defined as a direction orthogonal to a plane of the nozzle exit anddirecting from an inside of the nozzle to an outside of the nozzle, thefirst jet tab and the second jet tab are arranged in the first directionfrom the nozzle. The first jet tab includes: a first proximal sectionarranged so as not to overlaps with the nozzle exit in the firstdirection and connected with the first rotation axis; and a first tipsection configured to be moveable from a first standby position wherethe first jet tab does not overlaps with the nozzle exit, to a firstwork position where the first tip section overlaps with the nozzle exit.The second jet tab includes: a second proximal section arranged so asnot to overlaps with the nozzle exit in the first direction andconnected with the second rotation axis; and a second tip sectionconfigured to be moveable from a first standby position where the firstjet tab does not overlaps with the nozzle exit, to a first work positionwhere the first tip section overlaps with the nozzle exit. The first jettab and the second jet tab are symmetrically arranged with respect to apredetermined first symmetry plane, have a symmetrical shape withrespect to the first symmetry plane, and are driven symmetrically withrespect to the first symmetry plane by the driving section. A distancebetween a tip section of the first jet tab and the first rotation axisis larger than a distance between the first rotation axis and the firstsymmetry plane. A distance between a tip section of the second jet taband the second rotation axis is larger than a distance between thesecond rotation axis and the first symmetry plane. The thrust vectoringmethod includes: driving, by the driving section, the first jet tab fromthe first standby position to the first work position, and the secondjet tab from the second standby position to the second work position;and driving, by the driving section, the first jet tab from the firstwork position to the first standby position, and the second jet tab fromthe second work position to the second standby position, so that thedistance between the tip sections increase monotonously.

According to the present invention, the downsized and lightened thrustvectoring apparatus can be provided. In addition, the flying objectwhich includes the downsized and lightened thrust vectoring apparatuscan be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram schematically showing a main portion of a thrustvectoring apparatus.

FIG. 2A is a diagram showing a thrust vectoring angle.

FIG. 2B is a diagram showing an area of the opening of a nozzle exit.

FIG. 2C is a diagram showing an overlap area Ar.

FIG. 3 is a diagram showing a relation of the magnitude of a vectoringforce F and an area ratio S.

FIG. 4 is a diagram showing a force which a jet tab receives.

FIG. 5 is a perspective view of the thrust vectoring apparatus accordingto a first embodiment.

FIG. 6 is a partial expanded view around a first tab set.

FIG. 7 is a diagram showing the vectoring force obtained by the thrustvectoring apparatus according to the first embodiment.

FIG. 8 is a diagram showing the vectoring force obtained by the thrustvectoring apparatus in another example.

FIG. 9 is a side sectional view of the thrust vectoring apparatus aroundthe first jet tab.

FIG. 10 is a diagram showing the thrust vectoring apparatus 1 in a rearview.

FIG. 11 is a diagram showing an outer appearance of the first tab set ina work position.

FIG. 12 is a diagram showing another outer appearance of a jet tab.

FIG. 13 is a block diagram showing a drive system of the thrustvectoring apparatus.

FIG. 14 is a diagram showing a power dividing mechanism 50 correspondingto the first tab set.

FIG. 15 is a diagram showing the thrust vectoring apparatus 1B accordingto a second embodiment in the rear view.

FIG. 16 is a diagram showing the thrust vectoring apparatus 1C accordingto a third embodiment in the rear view.

FIG. 17 is a diagram showing an outer appearance of a flying objectaccording to a fourth embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the attached drawings. In the following embodiments, a samereference numeral is assigned to the same member. A serial numeral isused to distinguish the members with the same reference numeral.

(Principle of thrust vectoring apparatus)

FIG. 1 is a side sectional view schematically showing a thrust vectoringapparatus 1 a. The thrust vectoring apparatus 1 a includes a nozzle 10 aand a jet tab or tab 20 a. The diameter of the inner space of the nozzle10 a becomes larger in a direction of combustion gas G1 flow from athroat 14 a to a nozzle exit 11 a. A jet tab 20 a is arranged after thenozzle exit 11 a in a direction of a combustion gas flow. In FIG. 1, apart of s jet tab 20 a covers a part of the opening of the nozzle exit11 a.

The combustion gas G1 expands and flows in the direction from the throat14 a to the nozzle exit 11 a, and is exhausted from the nozzle exit 11a. In this case, a high-pressure region REG is generated in the internalspace of the nozzle 10 a due to the jet tab 20 a. In the high-pressureregion REG, the inflow of the combustion gas G1 is restrained. Adiagonal shock wave SHW is generated from a generation point SP of thehigh-pressure region REG. The combustion gas G1 is vectored or deflectedwith the diagonal shock wave SHW and exhausted from the nozzle exit 11 aas a vectored flow G2. At this time, vectoring force F is generated by aY-axial component (in a direction orthogonal to the central axis O ofthe nozzle 10 a) of the vectored flow G2. The thrust of a flying object(having the nozzle 10 a) is vectored with the vectoring force F.

(Shape of jet tab)

The shape of the jet tab is optional, and will be described withreference to FIG. 2A, FIG. 2B, FIG. 2C and FIG. 3. FIG. 2A is a diagramshowing a thrust vectoring angle. FIG. 2A shows a side view of a rocketmotor 7 and the nozzle 10 a. The thrust force Fx and the vectoring forceFy act on the rocket motor 7. The thrust force Fx is a force to act onthe direction of the central axis O. The vectoring force Fy is a forcecorresponding to the vectoring force F shown in FIG. 1. At this time,the thrust vectoring angle θ is defined as tan⁻¹ (Fy/Fx) (θ≧0). FIG. 2Bshows an opening A0 of the nozzle exit 11 a in a rear view from the rearside. The nozzle exit opening A0 represents an area the opening of thenozzle exit 11 a surrounded by the nozzle inner wall surface 12 a. FIG.2C shows an overlap area Ar that is an area of an overlap part where thejet tab 20 a covers the opening of the nozzle exit 11 a. In actual, aplurality of jet tabs 20 a are provided for the nozzle exit 11 a,although a single jet tab 20 a may be provided. Here, for simpledescription, a case of a single jet tab 20 a will be described as anexample.

FIG. 3 is a diagram showing a relation of the thrust vectoring angle θand an area ratio S as a ratio (S=Ar/A0) of the overlap area Ar to thenozzle exit opening area A0. At this time, the thrust vectoring angle θis shown as a monotonously increasing function of the area ratioS=Ar/A0. In other words, as the overlap area Ar increases, the thrustvectoring angle θ increases. Also, the vectoring force Fy shown in FIG.2A increases as the overlap area Ar substantially increases.

If the same vectoring force can be obtained, it is desirable that thesize of the jet tab is as small as possible. This leads the downsizingand lightening of the thrust vectoring apparatus. FIG. 4 is a diagramshowing a force which the jet tab 20 a receives. In this case, the jettab 20 has the shape of rectangular parallelepiped and is parallel to aplane orthogonal to the flow direction of the combustion gas G1 in thenozzle exit 11 a. The jet tab 20 a receives hydrodynamic force from thecombustion gas G1. In FIG. 4, a tip section 23 a of the jet tab 20 aoverlaps with the opening of the nozzle exit 11 a in the flow directionof the combustion gas G1 from the nozzle 10 a.

The combustion gas G1 is exhausted from the throat 14 a of the nozzle 10a toward the nozzle exit 11 a. At this time, the jet tab 20 roughlyreceives two types of force from the combustion gas G1. A first type offorce is a force F1 which a side surface 27 a of the jet tab 20 areceives. A second type of force is a force F2 which the surface 25 a ofthe jet tab 20 a receives. In the viewpoint of the hydrodynamics, thesetwo types of forces are dominant.

As shown in FIG. 4, the first type of force F1 acts perpendicularly tothe side surface 27 a of the jet tab 20 a. First, the jet tab 20 a is ina position where it does not overlap with the opening of the nozzle exit11 a (as shown by a two-dot chain line). Then, the jet tab 20 a isrotated by a driving section 30 a from the above position to a positionwhere it overlaps with the opening of the nozzle exit 11 a. At thistime, the driving section 30 a receives the force F1 to hinder therotation. By this force F1, a fluid load torque T is generated for thejet tab 20 a. The direction of the fluid load torque T is opposite tothe rotation direction of the jet tab 20 a. The magnitude of fluid loadtorque T is shown by the force F1×a span L1. The span L1 is a distanceto a position where the jet tab 20 receives the force F1, from aposition where the jet tab 20 a and a shaft 51 a are coupled. Note thatthe force F1 is a force which acts on some representative point. Inactual, the force which the jet tab 20 a receives is a summation offorces which act on respective points. Specifically, the fluid loadtorque T which the jet tab 20 a receives is a summation of the fluidload torques (F1×L1) which acts on respective points.

As shown in FIG. 4, the second type of force F2 acts perpendicularly tothe surface 25 a of the jet tab 20 a. The tip section 23 a of the jettab 20 a is pressed to the flow direction of the combustion gas G1 withthe force F2. By this force F2, the jet tab 20 a receives a bendingmoment M. The magnitude of the bending moment M is shown by the forceF2×the span L2. The span L2 is the distance to a position where the jettab 20 a receives the force F2, from the shaft 51. Note that the forceF2 is a force which acts on some representative point. In actual, theforce which the jet tab 20 a receives is a summation of forces which acton respective points. Specifically, the bending moment M which the jettab 20 a receives is a summation of the bending moments (F2×L2) whichact on the respective point.

If the thickness TH of the jet tab 20 a becomes thinner, the force F1which acts perpendicularly to the side surface 27 a of the jet tab 20 abecomes smaller, although the strength of the jet tab 20 a becomesweaker. On the other hand, if a part of the jet tab 20 a which overlapswith the opening of the nozzle exit 11 a becomes smaller, the force F2which acts perpendicularly to the surface 25 a of the jet tab 20 abecomes smaller. In this case, however, it becomes difficult to acquirea desired vectoring force F. Therefore, it is required to reduce theforces F1 and F2 acting on the jet tab 20 a as much as possible whilesecuring the desired vectoring force F.

First Embodiment (Overview)

The overview of a first embodiment will be described, with reference toFIG. 5 and FIG. 6. FIG. 5 is a perspective view of the thrust vectoringapparatus 1 according to the first embodiment. As shown in FIG. 5, thethrust vectoring apparatus 1 includes the nozzle 10, first to eighth jettabs 20 ₁ to 20 ₈, and a driving section. The first to eighth jet tabs20 ₁ to 20 ₈ have first to eighth rotation axes 21 ₁ to 21 ₈,respectively. The nozzle 10 includes the nozzle exit 11 and a nozzlebottom end 13. The driving section 30 rotates the first jet tab 20 ₁around the first rotation axis 21 ₁ and rotates the second jet tab 20 ₂around the second rotation axis 21 ₂.

In the present embodiment, in order to obtain the desired vectoringforce F while reducing the force applied to the jet tab 20, one tab setTAB is configured from two jet tabs 20. A first tab set TAB₁ includesthe first jet tab 20 ₁ and the second jet tab 20 ₂. In the same way, asecond tab set TAB₂ includes the third jet tab 20 ₃ and the fourth jettab 20 ₄. A third tab set TAB_(S) includes the fifth jet tab 20 ₅ andthe sixth jet tab 20 ₆. A fourth tab set TAB_(S) includes the seventhjet tab 20 ₇ and the eighth jet tab 20 ₈.

There are first to fourth symmetry planes SURa to SURd between the twojet tabs 20 of the respective tab sets TAB. In the first tab set TAB₁,there is the first symmetry plane SURa between the first jet tab 20 ₁and the second jet tab 20 ₂. The first jet tab 20 ₁ and the second jettab 20 ₂ are symmetrically arranged with respect to the first symmetryplane SURa and have a symmetrical shape with respect to the firstsymmetry plane SURa. Each of the jet tab sets has the same structure. Inthe following description, the first tab set TAB₁ will be described ifthere is not any especial matter.

FIG. 6 is a partial expanded view around the first tab set TAB₁. Asshown in FIG. 6, the first jet tab 20 ₁ further includes a firstproximal end 22 ₁ connected with first rotation axis 21 ₁ and a firsttip section 23 ₁. The second jet tab 20 ₂ further includes a secondproximal end 22 ₂ connected with the second rotation axis 21 ₂ and asecond tip section 23 ₂. Each of the first jet tab 20 ₁ and the secondjet tab 20 ₂ is arranged so as not to overlap with the opening of thenozzle exit 11 in the flow direction of the combustion gas. The drivingsection 30 rotates the first jet tab 20 ₁ and the second jet tab 20 ₂around the first rotation axis 21 ₁ and the second rotation axis 21 ₂,respectively. The first rotation axis 21 ₁ and the second rotation axis21 ₂ are apart from each other. The positions are both fixed.

Here, a distance between the first rotation axis 21 ₁ and a first tip 24₁ (a tip point on the first jet tab 20 ₁ which is most apart from thefirst rotation axis 21 ₁) is a distance D1. The distance to the firstsymmetry plane SURa from the first rotation axis 21 ₁ is D2. Thedistance between the second rotation axis 21 ₂ and the second tip 24 ₂(a tip point on the second jet tab 20 ₂ which is most apart from thesecond rotation axis 21 ₂) is D3. The distance to the first symmetryplane SURa from the second rotation axis 21 ₂ is D4.

The first jet tab 20 ₁ is driven in a range from a first standbyposition P1 ₁ to a first work position P2 ₁ by the driving section 30.The second jet tab 20 ₂ is driven in a range from the second standbyposition P1 ₂ to the second work position P2 ₂ by the driving section30.

When the first jet tab 20 ₁ is in the first standby position P1 ₁ andthe second jet tab 20 ₂ is in the second standby position P1 ₂, thefirst tip section 23 ₁ and the second tip section 23 ₂ do not face eachother.

When the first jet tab 20 ₁ is driven to the first work position P2 ₁from the first standby position P1 ₁ and the second jet tab 20 ₂ isdriven to the second work position P2 ₂ from the second standby positionP1 ₂, the first jet tab 20 ₁ and the second jet tab 20 ₂ aresymmetrically rotated in such a direction that they approach the firstsymmetry plane SURa monotonously and they are symmetrical with respectto the first symmetry plane SURa. Specifically, the first jet tab 20 ₁is rotated to the first work position P2 ₁ (shown by a two-dot chainline) from the first standby position P1 ₁ (shown by a solid line).Simultaneously, the second jet tab 20 ₂ is rotated to the second workposition P2 ₂ (shown by a two-dot chain line) from the second standbyposition P1 ₂ (shown by a solid line).

To realize this relation, the following relation should be satisfied.The distance between the first rotation axis 21 ₁ and the secondrotation axis 21 ₂ is shown by D5=D2+D4. The distance D5 is a constantvalue called a distance between the rotation axes. The distance betweena surface center 28 ₁ of the first tip section 23 ₁ and a surface center28 ₂ of the second tip section 23 ₂ is shown by D6. The distance D6 iscalled a distance between the tip sections. Here, the surface centershows a diagram center of a corresponding tip section 23. When the firstjet tab 20 ₁ is in the first standby position P1 ₁ and the second jettab 20 ₂ is in the second standby position P1 ₂, the distance D6 betweenthe tip sections is larger than the distance D5 between the rotationaxes.

The above-mentioned relation can be expressed as follows. Between thedistance D1 and the distance D2, the following relation should besatisfied. The distance D1 between the first tip section 24 ₁ and thefirst rotation axis 21 ₁ is larger than the distance D2 between thefirst rotation axis 21 ₁ and the first symmetry plane SURa of the firstjet tab 20 ₁. Moreover, the distance D3 and the distance D4 shouldsatisfy the following relation. In the second jet tab 20 ₂, the distanceD3 between the second tip section 24 ₂ and the second rotation axis 21 ₂is larger than the distance D4 between the second rotation axis 21 ₂ andthe first symmetry plane SURa.

(Operation (thrust vectoring method))

At the time of the thrust vectoring, the driving section 30 drives thefirst jet tab 20 ₁ from the first standby position P1 ₁ to the firstwork position P2 ₁ and drives the second jet tab 20 ₂ from the secondstandby position P1 ₂ to the second work position P2 ₂, so that thedistance D6 between the tip sections decreases monotonously. Contrary tothis, in case of cancellation of the thrust vectoring, the drivingsection 30 drives the first jet tab 20 ₁ from the first work position P2₁ to the first standby position P1 ₁, and drives the second jet tab 20 ₂from the second work position P2 ₂ to the second standby position P1 ₂,so that the distance D6 between the tip sections increases monotonously.

The above-mentioned relation exists on each of the jet tab sets TABs.Thus, the following effects are obtained. First, the reduction of fluidload torque T and the bending moment M is obtained. In the presentembodiment, one tab set TAB is configured from the two jet tabs 20.Here, it is supposed that the jet tabs of only one optional jet tab setTAB are in the work positions. If the overlap area Ar should be attainedby one jet tab, the surface area of the tip section of one jet tab (areaof the tip section 23 a in FIG. 4) becomes larger than one in thepresent embodiment. This means that the force F2 acting to the one jettab (referring to FIG. 4) increases and hinders the downsizing andlightening of the thrust vectoring apparatus. Therefore, in the presentembodiment, to reduce the force F2 acting on the one jet tab 20, one tabset TAB is configured from the two jet tabs 20. As a result, the bendingmoment M is reduced and the fluid load torque T is also reduced.

Second, the vectoring force increases. This will be described inrelation to FIG. 7 and FIG. 8. In FIG. 7, the vectoring force obtainedin the first embodiment is considered. In FIG. 8, a comparison exampleis considered.

FIG. 7 is a diagram showing the vectoring force obtained by the thrustvectoring apparatus 1 according to the first embodiment. Note that forsimple description, FIG. 7 shows only the first tab set TAB₁ which is inthe work position. The other tab sets TAB₂ to TAB₄ are in the standbypositions.

The first vectoring force F20 ₁ is generated by the first jet tab 20 ₁.The first vectoring force F20 ₁ acts in a direction from the centralaxis O of the nozzle 10 to the plane center 28 ₁ of the first tipsection 23 ₁ on the surface containing the nozzle exit 11. The firstvectoring force F20 ₁ is a vector force having an X axial component anda Y axial component. An angle between the first vectoring force F20 ₁and the Y axis is θ₁. Note that the Y axis is parallel to the firstsymmetry plane SURa.

The second vectoring force F20 ₂ is generated by the second jet tab 20₂. The second vectoring force F20 ₂ generated by the second jet tab 20 ₂acts in a direction from the central axis O of the nozzle 10 to theplane center 28 ₂ of the second tip section 23 ₂ on the plane orthogonalto the above direction in the nozzle exit 11. An angle between thesecond vectoring force F20 ₂ and the Y axis is θ₁ which is the same asin case of the first vectoring force F20 ₁. This is based on the shapesof the first jet tab 20 ₁ and the second jet tab 20 ₂ and thesymmetrical arrangement.

The vectoring force F20 generated by the first tab set TAB₁ is aresultant force of the first vectoring force F20 ₁ and the secondvectoring force F20 ₂. Therefore, as shown in FIG. 7, the vectoringforce F20 is generated in a direction approaching the nozzle inner wallsurface 12 from the central axis O of the nozzle 10 (a negativedirection of the Y axis).

FIG. 8 is a diagram showing the vectoring force obtained by anotherexample of the thrust vectoring apparatus 1A. The thrust vectoringapparatus 1A shown in FIG. 8 includes a first jet tab 20A₁ which rotatesaround a first rotation axis 21A₁ and a second jet tab 20A₂ whichrotates around the second rotation axis 21A₂. FIG. 8 shows a case whereboth of the first jet tab 20A₁ and the second jet tab 20A₂ are in workpositions. Basically, the thrust vectoring apparatus 1A shown in FIG. 8has the same structure as that shown in FIG. 7. Therefore, between thethrust vectoring apparatus 1 shown in FIG. 7 and the thrust vectoringapparatus 1A shown in FIG. 8, there is no difference in the overlap areaAr. However, there is a large difference in the following points.

The first difference is in the distance between the two rotation axes.The distance between the first rotation axis 21A₁ and the secondrotation axis 21A₂ shown in FIG. 8 is larger than the distance betweenthe first rotation axis 21 ₁ and the second rotation axis 21 ₂ shown inFIG. 7. The second difference is in that the rotation direction of thefirst jet tab 20A₁ and the rotation direction of the second jet tab 20A₂shown in FIG. 8 are opposite to those shows in FIG. 7 when two jet tabsmove from the standby positions to the work positions.

In other words, the arrangement shown in FIG. 8 is adopted so that thefirst tip section 23A₁ and the second tip section 23A₂ face each other,when both of the first jet tab 20A₁ and the second jet tab 20A₂ are inthe standby positions. This is different from the thrust vectoringapparatus 1 of the present embodiment.

The magnitude of the vectoring force F changes because of the twodifferences. In FIG. 8, the angle between the first vectoring forceF20A₁ and the Y axis is θ₂. This angle θ₂ is larger than the angle θ₁shown in FIG. 7 (θ₂>θ₁). This is the same for the second vectoring forceF2A₂. Therefore, the vectoring force F20A (=F20A₁+F20A₂) is smaller thanthe vectoring force F20 shown in FIG. 7 (F20A<F20).

As mentioned above, there is no difference in the overlap area Arbetween the thrust vectoring apparatus 1 shown in FIG. 7 and the thrustvectoring apparatus 1A shown in FIG. 8. Nevertheless, the vectoringforce F20 shown in FIG. 7 is larger than the vectoring force F20A showsin FIG. 8. In other words, the smaller jet tab in the example (thepresent embodiment) of FIG. 7 is enough to acquire an identicalvectoring force, compared with the example of FIG. 8. This leads thedownsizing and lightening of the thrust vectoring apparatus in additionto the downsizing of the driving section.

The third difference is in the point that the deviation of the vectoringforce (a misalignment) is very small. The deviation of the vectoringforce means a difference between the corresponding symmetry plane SURand the vectoring force. The first jet tab 20 ₁ and the second jet tab20 ₂ have a symmetrical shape with respect to the symmetry plane SURa.Moreover, the first jet tab 20 ₁ and the second jet tab 20 ₂ are drivento be symmetrical with respect to the first symmetry plane SURa.Therefore, the two vectoring forces F20 ₁ and F20 ₂ which aresymmetrical with respect to the first symmetry plane SURa are obtainedas shown in FIG. 7. As a result, the difference between the vectoringforce F20 as the resultant force of both and the first symmetry planeSURa is zero or very small. This symmetry contributes to the smalldeviation of the vectoring force.

(Standby position and work position)

The details of the standby position and the work position are asfollows. When the first jet tab 20 ₁ is in the first standby position P1₁, the first jet tab 20 ₁ is outside the opening of the nozzle exit 11so as not to overlap with the opening of the nozzle exit 11. Forexample, the first standby position P1 ₁ is a position where the wholeof the first jet tab 20 ₁ overlaps with the nozzle bottom end 13.

On the other hand, when the first jet tab 20 ₁ is in the first workposition P2 ₁, the first jet tab 20 ₁ is in a position where a part ofthe first jet tab 20 ₁ (the first tip section 23 ₁) overlaps with theopening of the nozzle exit 11. Specifically, the first work position P2₁ is a position where the thrust vectoring force by the first jet tab 20₁ and the second jet tab 20 ₂ becomes maximum.

When the second jet tab 20 ₂ is in the second standby position P1 ₂, thesecond jet tab 20 ₂ is outside the opening of the nozzle exit 11 so asnot to overlap with the opening of the nozzle exit 11. Specifically, thesecond standby position P1 ₂ is the position where the whole of thesecond jet tab 20 ₂ overlaps with the nozzle bottom end 13.

On the other hand, when the second jet tab 20 ₂ is in the second workposition P2 ₂, the part of the second jet tab 20 ₂ (the second tipsection 23 ₂) overlaps with the opening of the nozzle exit 11.Specifically, the second work position P2 ₂ is a position where thethrust vectoring force by the first jet tab 20 ₁ and the second jet tab20 ₂ becomes maximum.

Note that the attention should be paid to the following. It is assumedthat the required vectoring force is smaller than the maximum vectoringforce in case of design. In this case, the first work position P2 ₁ is aposition where the thrust vectoring force by the first jet tab 20 ₁ andthe second jet tab 20 ₂ is equal to the required vectoring force. In thesame way, the second work position P2 ₂ is a position where the thrustvectoring force by the first jet tab 20 ₁ and the second jet tab 20 ₂ isequal to the required vectoring force.

(Jet tab)

The first tip section 23 ₁ is a part of the first jet tab 20 ₁. Indetail, the first tip section 23 ₁ is a part of the first jet tab 20 ₁that overlaps with the opening of the nozzle exit 11 when the first jettab 20 ₁ is in the first work position P2 ₁. The first proximal section22 ₁ is a part of the first jet tab 20 ₁ except for the first tipsection 23 ₁. The second tip section 23 ₂ is a part of the second jettab 20 ₂. In detail, the second tip section 23 ₂ is a part of the secondjet tab 20 ₂ that overlaps with the opening of the nozzle exit 11 whenthe second jet tab 20 ₂ is in the second work position P2 ₂. The secondproximal section 22 ₂ is a part of the second jet tab 20 ₂ except forthe second tip section 23 ₂.

(Side section of thrust vectoring apparatus)

FIG. 9 is a side sectional view showing the periphery of the first jettab 20 ₁ of the thrust vectoring apparatus. FIG. 9 shows a conditionthat the first jet tab 20 ₁ is in the first work position P2 ₁.

The first jet tab 20 ₁ is arranged behind the nozzle bottom end 13 inthe flow direction of the combustion gas. The nozzle bottom end 13 is apart corresponding to the bottom of the nozzle 10. To simplify thedescription, the nozzle bottom end 13 is supposed to be flat in the rearview. The first rotation axis 21 ₁ is connected to the driving section30 through a shaft 51. Note that the shaft 51 may be the first rotationaxis 21 ₁. For example, the driving section 30 is arranged in the nozzle10 which is different from a space through which the combustion gas G1flows.

There is a small gap (a margin) GP between the surface 25 of the firstjet tab 20 ₁ and the nozzle bottom end 13. The width of the gap GP issufficient if the combustion gas G1 which flows into the gap GP is aslittle as possible, and the first jet tab 20 ₁ can rotate smoothlywithout any contact with the nozzle bottom end 13. Note that as the gapGP becomes large, an amount of the combustion gas G1 which flows intothe gap GP increases more. As a result, the pressure of thehigh-pressure region REG (referring to FIG. 1) decreases so that thevectoring force F becomes small.

(Arrangement of jet tab)

The jet tabs 20 of each of the jet tab sets TAB₁ to TAB₄ are arranged sothat the first to fourth tab sets TAB₁ to TAB₄ do not interferes witheach other, even when all of the first to fourth tab sets TAB₁ to TAB₄are driven at a same time.

FIG. 10 is a diagram showing the thrust vectoring apparatus 1 in therear view from. As shown in FIG. 10, the shape of the nozzle bottom end13 is circular in the view. The first to eighth jet tabs 20 ₁ to 20 ₈,i.e. the first to fourth tab sets TAB₁ to TAB₄ are arranged at an equalinterval along the circumferential shape of the nozzle bottom end 13.Paying the attention to the first tab set TAB₁ in the standby position,the first tip section 23 ₁ of the first jet tab 20 ₁ faces the eighthtip section 23 ₈ of the eighth jet tab 20 ₈. The second tip section 23 ₂of the second jet tab 20 ₂ faces the third tip section 233 of the thirdjet tab 20 ₃.

Note that the shape of the nozzle bottom end 13 is an example. Even ifthe nozzle bottom end 13 has another shape (for example, a shape exceptfor a circle), there is no problem.

The first to fourth tab sets TAB₁ to TAB₄ are arranged at the intervalof φ=90° in the circumferential direction. By adopting this angularinterval (φ), the first to eighth jet tabs 20 ₁ to 20 ₈ without anycontacts between the two neighboring jet tabs 20 can be arranged in thecircumferential direction without any contact. Moreover, when the firstto fourth tab sets TAB₁ to TAB₄ are driven from the standby position tothe work position (or oppositely), the two neighboring jet tabs 20 inthe circumferential direction of the first to eighth jet tabs 20 ₁ to 20₈ never contacts.

(Shape of jet tab)

To restrain the leakage of the combustion gas from the high-pressureregion REG, each of the jet tabs 20 has the following shape. FIG. 11 isa diagram showing an outer appearance of the first tab set TAB₁ in thework position. As shown in FIG. 11, the first jet tab 20 ₁ has a firstside surface 27 ₁. The second jet tab 20 ₂ has a second side surface 27₂. The first side surface 27 ₁ has a flat surface from the first tipsection 23 ₁ to the first proximal section 22 ₁. When the first tab setTAB₁ is in the work position, the first side surface 27 ₁ is parallel tothe first symmetry plane SURa. In the same way, the second side surface27 ₂ has a flat surface from the second tip section 23 ₂ to the secondproximal section 22 ₂. When the first tab set TAB₁ is in the workposition, the second side surface 27 ₂ is parallel to the first symmetryplane SURa. Therefore, when the first tab set TAB₁ is in the workposition, the first side surface 27 ₁ and the second side surface 27 ₂are parallel to each other in the flat surfaces.

At this time, a gap (a margin) GP2 exists between the first side surface27 ₁ the second side surface 27 ₂. The gap GP2 has a function ofpreventing the first side surface 27 ₁ and the second side surface 27 ₂from colliding each other when the first tab set TAB₁ is driven from thestandby position to the work position. Note that the gap GP2 between thefirst side surface 27 ₁ and the second side surface 27 ₂ may be from 1mm to about 5 mm. This distance is enough for prevention of collision ofthe first side surface 27 ₁ and the second side surface 27 ₂. Theleakage of the combustion gas to the direction not contributing to thegeneration of the vectoring force, from the high-pressure region REG issufficiently suppressed when the gap GP2 is equal to or larger than 1 mmand equal to or less than 5 mm.

As described above, it is necessary that each of the first to eighth jettabs 20 ₁ to 20 ₈ has such a shape that the two jet tabs 20 neighboringin the circumferential direction do not contact regardless of thepositions. Moreover, it is necessary that each of the first to eighthjet tabs 20 ₁ to 20 ₈ has such a shape that the jet tab does not contactthe jet tab 20 opposing with respect to the central axis O.

For this purpose, the shape of each jet tab 20 of each of the jet tabsets TAB₁ to TAB₄ is set so that each of the first to fourth tab setsTAB₁ to TAB₄ does not interferes with any other jet tab set TAB, even ifall of the first to fourth jet tab sets TAB₁ to TAB₄ are driven at thesame time.

There are the first to fourth planes SUR₁ to SUR₄ between two of thefirst to fourth tab sets TAB₁ to TAB₄. The first plane SUR₁ is a planebetween the first tab set TAB₁ and the second tab set TAB₂. In the sameway, the fourth plane SUR₄ is a plane between the first tab set TAB₁ andthe fourth tab set TAB₄. When the first tab set TAB₁ is driven from thestandby position to the work position (or oppositely), the loci of thefirst tip section 24 ₁ and the second tip section 24 ₂ (referring to thebroken line in FIG. 10) must exist inside the first plane SUR₁ andfourth plane SUR₄.

The first tip section 23 ₁ has a shape becoming thinner toward the tip(the first tip section 24 ₁). In the same way, the second tip section 23₂ has a shape becoming thinner toward the tip (the second tip section 24₂). Thus, when the first tab set TAB₁ is driven from the standbyposition to the work position, the locus of the first tip section 24 ₁(referring to the broken line in FIG. 10) falls in a region between thefirst symmetry plane SURa and the fourth plane SUR₄. The locus of thesecond tip section 24 ₂ falls within a region between the first symmetryplane SURa and the first plane SUR₁. Moreover, the plane center 28 ₁ ofthe first tip section 23 ₁ approaches the side of the first proximalsection 22 ₁, and the plane center 28 ₂ of the second tip section 23 ₂approaches the side of the second proximal section 22 ₂. As a result,the span L2 (see FIG. 4) becomes short so that the bending moment Mdecreases.

In the first jet tab 20 ₁, the thickness TH₁ of the first tip section 23₁ is thinner than the thickness TH₂ of the first proximal section 22 ₁.In the same way, in the second jet tab 20 ₂, the thickness TH₁ of thesecond tip section 23 ₂ is thinner than the thickness TH₂ of the secondproximal section 22 ₂. Specifically, the thickness of the first jet tab20 ₁ becomes thinner gradually to the first tip section 23 ₁ from thefirst proximal section 22 ₁. The thickness of the second jet tab 20 ₂becomes thinner gradually to the second tip section 23 ₂ from the secondproximal section 22 ₂. Thus, the advantage can be acquired that the jettab can endure the force F2 (referring to FIG. 4) pressed by thecombustion gas in the necessary and minimum thickness.

(Other shape of jet tab)

The jet tab having the following shape may be used from theabove-mentioned signification. FIG. 12 is a diagram showing an outerappearance of the other shape of the jet tab 20. As shown in FIG. 12,the first jet tab 20B₁ has a shape becoming thinner gradually toward thefirst tip section 23 ₁ from the first proximal section 22 ₁. In the sameway, the second jet tab 20B₂ has a shape becoming thinner graduallytoward the second tip section 23 ₂ from the second proximal section 22₂. In this example, the distance D1 between the first tip section 24 ₁and the first rotation axis 21 ₁ is larger than the distance D2 betweenthe first rotation axis 21 ₁ and the first symmetry plane SURa.Moreover, the distance D3 between the second tip section 24 ₂ and thesecond rotation axis 21 ₂ is larger than the distance D4 between thesecond rotation axis 21 ₂ and the first symmetry plane SURa.Theoretically, it is not required that the shapes of the jet tabs usedin the thrust vectoring apparatus 1 are always identical. However, inthe practical viewpoint, it is desirable that the shapes of the first toeighth jet tabs 20 ₁ to 20 ₈ are completely same.

(Driving system)

The drive system of the thrust vectoring apparatus 1 will be described.FIG. 13 is a block diagram showing the driving system of the thrustvectoring apparatus 1. The thrust vectoring apparatus 1 includes firstto eighth driving sections 30 ₁ to 30 ₈, first to eighth drivingmechanisms 33 ₁ to 33 ₈ and a drive control section 40.

Each of the first to eighth driving sections 30 ₁ to 30 ₈ includes amotor as an actuator. The first to eighth driving sections 30 ₁ to 30 ₈are connected respectively to the first to eighth driving mechanisms 33₁ to 33 ₈. The first to eighth driving sections 30 ₁ to 30 ₈ generatedriving forces (rotation forces) under the control of the drive controlsection 40. The driving section 30 of the first to eighth drivingsections 30 ₁ to 30 ₈ which is controlled by the drive control section40 gives the generated driving force to a corresponding drivingmechanism 33.

The first driving mechanism 33 ₁ is configured to rotate the first jettab 20 ₁ around the first rotation axis 21 ₁. The second drivingmechanism 33 ₂ is configured to rotate the second jet tab 20 ₂ aroundthe second rotation axis 21 ₂. The third driving mechanism 33 ₃ isconfigured to rotate the third jet tab 20 ₃ around the third rotationaxis 21 ₃. The fourth driving mechanism 33 ₄ is configured to rotate thefourth jet tab 20 ₄ around the fourth rotation axis 21 ₄. The fifthdriving mechanism 33 ₅ is configured to rotate the fifth jet tab 20 ₅around the fifth rotation axis 21 ₅. The sixth driving mechanism 33 ₆ isconfigured to rotate the sixth jet tab 20 ₆ around the sixth rotationaxis 21 ₆. The seventh driving mechanism 33 ₇ is configured to rotatethe seventh jet tab 20 ₇ around the seventh rotation axis 21 ₇. Theeighth driving mechanism 33 ₈ is configured to rotate the eighth jet tab20 ₈ around the eighth rotation axis 21 ₁.

The drive control section 40 totally controls the whole driving system.The drive control unit 40 includes a microprocessor, a memory andvarious electronic circuits. The drive control section 40 iselectrically connected with the first to eighth driving sections 30 ₁ to30 ₈. The drive control section 40 drives at least one driving sectioncorresponding to the jet tab set TAB as a drive object, of the first toeighth driving sections 30 ₁ to 30 ₈. For example, when the tab set TABto be driven to acquire the desired vectoring force is the first tab setTAB₁, the drive control section 40 executes the following control. Thatis, the drive control section 40 controls the first driving section 30 ₁and the second driving section 30 ₂ synchronously to move the first jettab 20 ₁ and the second jet tab 20 ₂ symmetrically with respect to thefirst symmetry plane SURa.

(Power dividing mechanism (modification of driving system))

In the above-mentioned example, one driving section is provided for onejet tab 20. It is desirable that the numbers of driving sections is lessfrom the viewpoint of the downsizing and lightening of the thrustvectoring apparatus. Accordingly, an example that one driving section isprovided for two jet tabs 20 will be described below.

FIG. 14 is a diagram showing an outer appearance of a power dividingmechanism 50. FIG. 14 is a diagram showing the power dividing mechanism50 corresponding to the first tab set TAB₁. Actually, the one powerdividing mechanism 50 is provided for one tab set of TAB. In otherwords, the thrust vectoring apparatus 1 includes the power dividingmechanism 50 to each of the first to fourth tab sets TAB₁ to TAB₄.

The power dividing mechanism 50 is a mechanism of transferring thedriving force of the driving section 30 to the first jet tab 20 ₁ andthe second jet tab 20 ₂ at the same time. The power dividing mechanism50 includes a first shaft 51 ₁, a first gear 52 ₁, a second shaft 51 ₂and a second gear 52 ₂. The proximal section 511 ₁ of the first shaft 51₁ is released. The tip section 512 ₁ of the first shaft 51 ₁ isconnected to the first jet tab 20 ₁. Note that the first shaft 51 ₁ andthe first jet tab 20 ₁ may be formed as a unitary body. The first gear52 ₁ is disposed on the first shaft 51 ₁. The proximal section 511 ₂ ofthe second shaft 51 ₂ is connected to the first driving section 30 ₁.The tip section 512 ₂ of the second shaft 51 ₂ is connected to thesecond jet tab 20 ₂. Note that the second shaft 51 ₂ and the second jettab 20 ₂ may be formed as a unitary body. The second gear 52 ₂ isdisposed on the second shaft 51 ₂. In this case, the first gear 52 ₁ isdisposed to engage with the second gear 52 ₂. Here, the first gear 52 ₁engages with the second gear 52 ₂ so that the rotation direction of thefirst gear 52 ₁ opposite to the rotation direction of the second gear 52₂.

The operation of the power dividing mechanism 50 is as follows. Here, acase where the first tab set TAB₁ is driven from the standby position tothe work position will be described. First, the drive control section 40sends a control signal to the first driving section 30 ₁. For example,the control signal is an electric signal with a high level. The controlsignal is sent to the first driving section 30 ₁ until the first tab setTAB₁ is driven to the work position. When receiving the control signalfrom the drive control section 40, the first driving section 30 ₁rotates the second shaft 51 ₂. The rotation direction is a direction ofthe Y axis (positive) from the X axis (positive). The rotation of thesecond shaft 51 ₂ is carried out for a period during which the controlsignal is received. When the second shaft 51 ₂ rotates, the second gear52 ₂ rotates in a same rotation direction as the rotation direction ofthe second shaft 51 ₂. Then, the rotation of the second gear 52 ₂ istransferred to the first gear 52 ₁. In this case, the rotation directionof the first gear 52 ₁ is a direction opposite to the rotation directionof the second gear 52 ₂. When the first gear 52 ₁ rotates, the firstshaft 51 ₁ synchronously rotates in a direction opposite to the rotationdirection of the second shaft 51 ₂.

One driving section is disposed for the two jet tabs 20. Therefore, thenumber of driving sections is decreased to a half, comparing thestructure shown in FIG. 13 with the structure shown in FIG. 14. This isuseful for downsizing and lighting of the thrust vectoring apparatus 1.

As described above, the downsizing of the driving section and downsizingof the jet tab becomes possible, according to the first embodiment. Thisleads the downsizing and lightening of the thrust vectoring apparatus.

Second Embodiment

In the first embodiment, eight jet tabs 20 ₁ to 20 ₈ are used. However,the jet tabs 20 more than eight may be used in a second embodiment.

FIG. 15 is a diagram showing the thrust vectoring apparatus 1B accordingto the second embodiment in the rear view. In the present embodiment, 12jet tabs 20 ₁ to 20 ₁₂ are disposed. In other words, there are six tabssets TAB₁ to TAB₆. There are the first to sixth symmetry planes SURa toSURf which are provided between two jet tabs 20 of each tab set TAB.

Below, a difference from the first embodiment will be described. A fifthtab set TAB₅ includes a ninth jet tab 20 ₉ and a tenth jet tab 20 ₁₀. Asixth tab set TAB₆ includes an eleventh jet tab 20 ₁₁ and a twelfth jettab 20 ₁₂.

The first to sixth tab sets TAB₁ to TAB₆ are arranged at the interval ofφ=60° in the circumferential direction. Even in the present embodiment,the arrangement of the jet tabs 20 of each of the jet tab sets TAB₁ toTAB₆ is determined so that the first to sixth tab sets TAB₁ to TAB₆ donot interferes with each other.

Even if the number of jet tabs 20 increases like the present embodiment,the same effect as described in the first embodiment is attained.

Third Embodiment

In a third embodiment, a case where the number of jet tabs 20 is lessthan eight will be described. FIG. 16 is a diagram showing the thrustvectoring apparatus 1C according to the third embodiment in the rearview. In the present embodiment, six jet tabs 20 ₁ to 20 ₆ are disposed.In other words, there are three tabs sets TAB₁ to TAB₃. The first tothird symmetry planes SURa to SURc are present between two jet tabs 20of each tab set TAB.

The first to third tab sets TAB₁ to TAB₃ are arranged at the interval ofφ=120° in the circumferential direction. Even in the present embodiment,the arrangement of the jet tabs 20 in each of the tab sets TAB₁ to TAB₃is determined so that the first to third tab sets TAB₁ to TAB₃ do notinterfere with each other.

Even if the number of jet tabs 20 decreases like the present embodiment,the same effect as described in the first embodiment is obtained.

Modification Example 1

To reduce the number of driving sections, one tab set TAB may beconfigured from equal to or more than two jet tabs 20. Note that thenumber of jet tabs 20 is even numbered (e.g. four). In this case, onedriving section drives all the jet tabs 20. This becomes possible bydevising the power dividing mechanism 50. For example, a configurationthat a plurality of gears are disposed and the plurality of gears aresuitably combined is thought of. However, when the number of jet tabs 20of one tab set TAB increases, the mechanism of the driving systembecomes complicated.

Modification Example 2

To reduce the number of driving sections, a plurality of tab sets TABs(e.g. two) may be driven by one driving section. In this case, itbecomes possible by devising the power dividing mechanism 50 like themodification example 1. However, when the number of tab sets TABs whichare driven by one driving section increases, a mechanism of the drivingsystem becomes complicated.

Fourth Embodiment

The thrust vectoring apparatus 1 according to the first embodiment issuitable for a flying object exemplified by a missile. FIG. 17 is adiagram showing the outer appearance of the flying object 6 according toa fourth embodiment. The flying object 6 includes the thrust vectoringapparatus 1 according to the first embodiment and a plurality ofsteering wing 61. Because the flying object 6 includes the thrustvectoring apparatus 1, it is useful to downsize and to lighten theflying object 6. Of course, the thrust vectoring apparatus 1B accordingto the second or third embodiment instead of the thrust vectoringapparatus 1, 1 C may be used.

As such, the above embodiments, examples and modifications may becombined optionally in a range of no technical contradiction. Variousmodifications are carried out in a range where the features of thepresent invention are not changed.

What is claimed is:
 1. A thrust vectoring apparatus comprising: a nozzlehaving an opening of a nozzle exit from which a combustion gas isexhausted; a plurality of tab sets, each of which comprises at least onetab, which is disposed outside the nozzle exit opening not to cover anypart of the nozzle exit opening in a standby state; and a drivingsection configured to drive said at least one tab for said tab set fromthe standby state to a work state such that a direction of thrust by thecombustion gas is vectored by covering a part of the nozzle exit openingby a tip section of said at least one tab.
 2. The thrust vectoringapparatus according to claim 1, further comprising: a drive controlsection configured to issue a control signal to said driving section,wherein said driving section drives said at least one tab for said tabset from the standby state to the work state in response to the controlsignal such that the tip section of said at least one tab covers thepart of the nozzle exit opening.
 3. The thrust vectoring apparatusaccording to claim 2, wherein each of said plurality of tab setscomprises two tabs, and wherein said driving section drives said twotabs for said tab set from the standby state to the work state inresponse to the control signal such that the tip sections of said twotabs cover the part of the nozzle exit opening.
 4. The thrust vectoringapparatus according to claim 3, wherein said two tabs are disposed insymmetry with respect to a symmetrical plane between said two tabs,wherein said driving section drives said two tabs in symmetry withrespect to the symmetrical plane.
 5. The thrust vectoring apparatusaccording to claim 3, wherein said driving section comprises two driveactuators configured to drive said two tabs from the standby state tothe work state in response to the control signal, respectively.
 6. Thethrust vectoring apparatus according to claim 1, wherein each of saidplurality of tab sets comprises a plurality of tabs, and wherein saiddriving section comprises a single drive actuator such that saidplurality of tabs are driven from the standby state to the work state bysaid single drive actuator.
 7. The thrust vectoring apparatus accordingto claim 6, further comprising: a power dividing mechanism configured totransfer a power of said driving section to said plurality of tabs,wherein said power dividing mechanism comprises: a rotation shaftconnected to each of said plurality of tabs; and a gear disposed forsaid rotation shaft, wherein, when said driving section is driven, saidplurality of gears are engaged one after another such that saidplurality of tabs are driven from the standby state to the work state.8. The thrust vectoring apparatus according to claim 1, wherein said atleast one tab has a tip section and a proximal section, and a thicknessof said at least one tab becomes thinner toward the tip section from theproximal section.
 9. The thrust vectoring apparatus according to claim1, wherein said plurality of tab sets are arranged so that saidplurality of tab sets do not interfere with each other even if saidplurality of tab sets are driven at a same time.
 10. A flying objectcomprising: a nozzle having an opening of a nozzle exit from which acombustion gas is exhausted; a plurality of tab sets, each of whichcomprises at least a tab, which is disposed outside the nozzle exitopening not to cover any part of the nozzle exit opening in a standbystate; and a driving section configured to drive said at least one tabfor said tab set from the standby state to a work state such that adirection of thrust by the combustion gas is vectored by covering a partof the nozzle exit opening by a tip section of said at least one tab.11. The flying object according to claim 10, further comprising: a drivecontrol section configured to issue a control signal to said drivingsection, wherein said driving section drives said at least one tab forsaid tab set from the standby state to the work state in response to thecontrol signal such that the tip section of said at least one tab coversthe part of the nozzle exit opening.
 12. The flying object according toclaim 11, wherein each of said plurality of tab sets comprises two tabs,and wherein said driving section drives said two tabs for said tab setfrom the standby state to the work state in response to the controlsignal such that the tip sections of said two tabs cover the part of thenozzle exit opening.
 13. The flying object according to claim 12,wherein said two tabs are disposed in symmetry with respect to asymmetrical plane between said two tabs, wherein said driving sectiondrives said two tabs in symmetry with respect to the symmetrical plane.14. The flying object according to claim 12, wherein said drivingsection comprises two drive actuators configured to drive said two tabsfrom the standby state to the work state in response to the controlsignal, respectively.
 15. The flying object according to claim 10,wherein each of said plurality of tab sets comprises a plurality oftabs, and wherein said driving section comprises a single drive actuatorsuch that said plurality of tabs are driven from the standby state tothe work state by said single drive actuator.
 16. The flying objectaccording to claim 15, further comprising: a power dividing mechanismconfigured to transfer a power of said driving section to said pluralityof tabs, wherein said power dividing mechanism comprises: a rotationshaft connected to each of said plurality of tabs; and a gear disposedfor said rotation shaft, wherein, when said driving section is driven,said plurality of gears are engaged one after another such that saidplurality of tabs are driven from the standby state to the work state.17. The flying object according to claim 10, wherein said at least onetab has a tip section and a proximal section, and a thickness of said atleast one tab becomes thinner toward the tip section from the proximalsection.
 18. The flying object according to claim 10, wherein saidplurality of tab sets are arranged so that said plurality of tab sets donot interfere with each other even if said plurality of tab sets aredriven at a same time.
 19. A thrust vectoring method comprising:disposing a plurality of tab sets outside an opening of a nozzle exitnot to cover any part of the nozzle exit opening in a standby state,wherein each of said plurality of tab sets comprises at least a tab;driving said at least one tab for said tab set from the standby state toa work state to cover a part of the nozzle exit opening by a tip sectionof said at least one tab; and vectoring a direction of thrust by thecombustion gas in a nozzle by said at least one tab.